By: Alex Korter
The Administration Replacement Building (ARB) represents the aspirations and mission of Cal Poly Pomona, which is a student-centered university with an emphasis on the union of engineering, agriculture and environmental design. This union is primarily expressed by the undulating, aluminum roof which takes inspiration from the surrounding hills that define the campus to create its unusual, contextual shape.
Perhaps more importantly, the roof serves an essential role in passive solar design. Its large, perforated overhangs shade the exterior glass – significantly reducing solar heat gain loads and glare – but also filter and reflect daylight to the interior, reducing the electrical lighting loads. The roof also provides welcome thermal comfort to the pedestrian passageway leading from the main parking area to the student union and library, creating a shaded street leading to the heart of the campus.
Extensive coordination is taking place to optimize the steel framing and minimize the use of atypical shapes. By measuring the distance between the underside of the curved roof surface and the top of staight steel members, the roof geometry and/or steel members can be adjusted to constructable tolerances. In addition, the standing seam roof panelization – which consists of 16″-wide planks – is also continuously reviewed to keep tapered and freeform panel shapes to a minimum.
As the main energy performance driver, the perforated roof overhangs are being analyzed to determine the optimal depths based on solar orientation. The level of perforation of the aluminum panels was also carefully selected to achieve a fine balance between solar heat gain/glare reduction and maximum daylighting benefits within the program spaces. Paired with the thermal mass of the cast-in-place concrete floors, the roof shading contributes to a 30% reduction of the cooling load and 20% of the fan and pump energy loads.